Process of making potassium bichromate



UNITED STATES PATENT OFFICE.

WILLIAM SIMON, OF BALTIMORE, MARYLAND.

PROCESS OF MAKING POTASSIUM BICHROIVIATE.

SPECIFICATION forming part of Letters Patent No. 366,036, dated July 5, 1887.

Application filed December 2, 1885. Serial No. 184,464. (No specimens.)

T in whom it may concern:

Be it known that 1, WIL IAM SIMON, a citizen of the United States, residing in the city of Baltimore and State of Maryland, have invented certain new and useful Improvements in the Manufacture of Bichromate of Potash, of which the following is a full and clear description.

My method for the manufacture of bichromate of potassium consists in the conversion of chromate of sodium into bichromate of potassium by the addition of sulphate of potas sium and of either hydrochloric or sulphuric acid to a solution of said chromate of sodium, when decomposition takes place, bichromatc of potassium being formed, which is separated by crystallization, while thc s o dium salts l Ta,,Cr,O K 80 Bichromate of Sulphate of sodium. potassium.

Second way: To chromate of sodium, or to a solution of this salt, are added sulphuric acid and sulphate of potassium, when bichro mate of potassium separates in crystals and is collected, while sulphate of sodium is ob (chloride or sulphate of sodium) which are formed may be obtained by boiling down the mother-liquor.

The above process may be carried out in two different ways, as follows:

First way: Ohromate of sodium, or a solution of this salt, is converted into bichromate of sodium by the addition of a mineral acid in the Well-known way, and then to the solution of bichromate of sodium thus obtained, and also containing a soda salt of the acid employed, (which soda salt may or may not be separatedby'boiling down to a sufficient strength,) is added sulphate of potassium, when the decomposition takes place, which is represented by the following equation:

K,or,o, Na,SO, Bichromate of Sulphate of potassium. sodium.

tained by boiling down the mother-liquor and removing this salt, and from which motherliquor again bichromate of potassium crystallizes 011 cooling. The decomposition taking place is shown by the following equation:

2(Na,GrO,) K,SO,, H,SO X 0150, 2Na,SO, H 0 Ohromate of Sulphate of Sulphuric Bichromate of Sulphate of Vater. sodium. acid. potassium. sodium.

\Vhat I claim ischromate of sodium by sulphate of potassium 1. The process ofmanufacturing bichromate and sulphuric acid, substantially as described.

of potassium which consists in decomposing bichromateofsodiumbysnlphate of potassium, substantially as described.

2. The process of manufacturing bichroniate of potassium which consists in decomposing WILLIAM SllMON. 

